The Prince George’s County Council voted unanimously Tuesday to bar all county agencies from engaging in immigration enforcement — a change that council members say is necessary to reduce fear among a growing immigrant population.

The bill, sponsored by 10 of the council’s 11 members, was opposed by the Prince George’s County Police Department, which says it’s unnecessary because of an existing policy barring officers from working with U.S. Immigration and Customs Enforcement unless individuals face criminal warrants.

The council proposed the bill following the revelation that several county residents were nevertheless placed in deportation proceedings after contact with police — actions that Police Chief Hank Stawinski said were mistakes.

Stawinski joined County Executive Angela D. Alsobrooks (D) this summer in issuing the current administrative policy, more clearly barring cooperation with ICE, after those erroneous arrests were brought to the attention of the executive branch.

But members of the all-Democratic council say the policy needed to be codified into law and extended to apply throughout the county government.

“There is an incredible amount of fear,” said council member Deni Taveras (D-District 2), who sponsored the legislation. “These people pay taxes . . . we need to be doing better at all levels of government in terms of protecting them.”

Immigrants, advocates and local officials packed the hearing room Tuesday to support the bill, saying it is necessary to ensure that immigrants feel comfortable interacting with police, including reporting crimes and serving as witnesses. Alsobrooks spokesman John Erzen said he anticipates she will sign the bill.

The bill was part of a package supported by Casa de Maryland, the state’s largest immigrant advocacy group, that also included bills to require residents to be alerted when they are placed in a gang database and to require police to wear body cameras. Those bills did not advance.

Several municipalities in Prince George’s, including Hyattsville, Greenbelt and Forest Heights, have passed their own cooperation bans at the urging of immigrant advocates, who are seeking to strengthen local protections for undocumented residents as the Trump administration tries to increase enforcement.

Neighboring Montgomery County and the District have explicit general orders barring all agencies from cooperation with federal immigration efforts but have not codified those orders through legislation.

Advocates at Casa said they are prepared to push statewide legislation barring cooperation, which would essentially define Maryland as a sanctuary state. A sanctuary bill failed in Annapolis in 2017, but advocates say they are more hopeful about their chances in 2020, given new leadership in both the House of Delegates and state Senate.

Also Tuesday, the last scheduled voting session of the fall term, the council approved — over objections from residents — a controversial zoning measure that will allow single-family homes and town homes to be built on land where a small airport currently operates. The site is just outside Bowie, whose newly elected mayor, Timothy Adams (D), was among those who testified that already-congested roads in the area will not be able to handle increased residential density.

Council member Derrick Leon Davis (D-District 6), who sponsored the bill, said there had been sufficient public input over the course of 10 months. He said the vote was the “beginning of the beginning” in terms of determining the details of developing the site, with additional discussion by the planning board.

The measure was opposed by the county’s planning board, which has generally refused to support “text amendments” that it considers to be site-specific. The council approved the bill 7-4. The “no” votes included council member Thomas E. Dernoga (D-District 1), who said the bill was “a clear case of spot zoning” and inconsistent with good planning principles.

The use of text amendments also attracted scrutiny this year when it was used to pave the way for an Amazon warehouse in a residential part of Upper Marlboro. That project was later shelved amid strong community opposition. (Amazon founder Jeff Bezos owns The Washington Post.)

The council unanimously approved an overhaul of the county’s animal-control ordinance, after rejecting an amendment last month that would have removed the county’s ban on pit bulls. The bill allows the county to apply criminal penalties to owners of dogs that attack people, regardless of breed, and makes it illegal to keep dogs chained outside.

More than a dozen residents testified about the bill. Some who supported the legislation had personal experiences with pit bull attacks. Opponents, including volunteers from the county animal shelter, said the ban is ineffective and inhumane and urged the council to reconsider the issue in 2020.

The council also confirmed Major F. Riddick Jr. as Alsobrooks’s chief administrative officer — one of the two top positions in her cabinet. Riddick, a lobbyist and longtime aide to former governor Parris Glendening (D), has been serving in that role on an interim basis since Alsobrooks took office in December.